CN102671617B - A preparation method of a material for adsorbing refractory organic pollutants - Google Patents

Abstract

The invention relates to a preparation method of a material for adsorbing refractory organic pollutants. With nano-iron, magnesium salt, aluminum salt and caustic soda as inorganic reactants and anionic surfactant as functional agent, after mixing the anionic surfactant and nano-iron evenly, add it to the mixed solution of caustic soda and aluminum salt, mix Mix well, then slowly add magnesium salt solution, mix for 10-30 minutes, let stand for more than 12 hours, separate and obtain blue precipitate, which is the material used to adsorb refractory organic pollutants including dyes or persistent organic compounds. The material is added into organic waste water by 0.1-1%, and has excellent adsorption performance and magnetic separation performance. The invention has the advantages of easy-to-obtain raw materials, simple process, low cost, large adsorption capacity of dyes or hydrophobic organic matter, good magnetic separation effect, etc., and can be used for adsorption treatment of organic industrial wastewater.

Description

A preparation method of a material for adsorbing refractory organic pollutants

technical field

The invention relates to a preparation method of a material for adsorbing refractory organic pollutants, in particular to a production process of an adsorption material for treating organic waste water. It belongs to the field of environmental pollution control.

Background technique

A large amount of waste water is discharged into the environment during the production of dyes, medicines, pesticides, and chemicals. High concentrations of organic matter, especially persistent organic pollutants, have brought serious disasters to humans and the ecological environment. For example, more than 10,000 dyes have been produced commercially, with 5%-10% of the amount used being discharged into the aquatic environment. Most of the dye molecules contain aromatic groups, which are resistant to light, heat, and oxidation. Some dyes can cause allergies, dermatitis, redness and swelling of the skin, and even induce cancer and gene mutations. Therefore, organic pollutants in wastewater must be removed before entering natural water bodies. Organic wastewater treatment methods mainly include physical, chemical and biological methods. Physical methods mainly include: membrane separation method, magnetic separation method and adsorption method. Membrane separation method to treat organic and colored wastewater began in the early 1970s. However, the price of the membrane is higher, the replacement frequency is faster, and the disposal cost is higher. Magnetic separation is a process of using the difference in magnetic susceptibility of elements or components to treat the material with the help of an external magnetic field, so as to achieve enhanced separation. It has become an emerging water treatment technology. Adsorption is the use of some solids with porous surfaces as adsorbents. When the wastewater is in contact with the adsorbent, one or several pollutants in the wastewater are adsorbed on the solid surface to achieve the purpose of wastewater purification. In the treatment of organic wastewater, the adsorption method is mainly used for pretreatment or advanced treatment after biochemical treatment. Adsorption method has a wide range of applications and is not specific. Adsorbents are divided into artificial and natural adsorbents. Commonly used adsorbents include activated carbon, alumina, wood chips, natural clay, rice milling waste, silica gel, hydroxide, sludge, living microorganisms or dead cells, etc., but most of them are The adsorption equilibrium time is long, the effect after regeneration is obviously reduced, the selectivity is poor, and the reduction of chemical oxygen demand (COD) is small. Activated carbon adsorption is currently the most widely used organic and colored wastewater treatment method, but activated carbon adsorption takes a long time and regeneration is difficult. Bentonite has a large reserve in my country and is cheap. People often use surfactants to modify bentonite, and the adsorption performance can be 1 to 2 orders of magnitude higher than that of the original soil. When used in organic wastewater treatment, surface modification is prone to desorption of surfactants. Although the concentration of organic matter in wastewater is reduced, the reduction of COD is not obvious. Chemical methods are mainly divided into coagulation precipitation method, oxidation method and electrochemical method. Coagulation and sedimentation technology is the main step in the primary treatment of wastewater. It is a technology that uses the charging characteristics of the dye itself to mix two or more oppositely charged sewage, or uses a coagulant to mix sewage. The flocculant plays a major role in the flocculation and sedimentation process, but the traditional low molecular weight flocculant has a large dosage and produces a large amount of sludge. Conventional coagulants are used in the treatment of some water-soluble, especially in the treatment of cationic dyes and reactive dye wastewater, the decolorization effect of flocculants alone is not ideal. Oxidation methods are divided into chemical oxidation methods and advanced oxidation methods, both of which are treatment processes that oxidize and destroy the color-forming genes of dyes and decolorize them. Advanced oxidation technology includes wet oxidation method, Fenton reagent method and photocatalytic oxidation method, etc., which have good decolorization ability, but the cost is high, and the COD reduction effect is not good. Electrochemical technology to treat wastewater has multiple functions such as redox, coagulation, sterilization, and adsorption. However, the complete oxidation and decomposition of organic pollutants in water requires high energy consumption and high equipment costs. The use of microbial methods to adsorb organic matter has been gradually developed in recent years. This method has the advantages of no waste and complete utilization, but the decolorization cycle is long and has certain requirements for the environment. Because organic pollutants, especially persistent organic pollutants, are harmful to the environment and human health, it is of great significance to design and prepare new adsorption materials with high adsorption efficiency and good adsorption and separation performance to eliminate pollution.

Contents of the invention

The purpose of the present invention is to disclose a material preparation method for adsorption of typical organic pollutants. The adsorption material of refractory organic pollutants (dyes, persistent organic pollutants, etc.) obtained by the method of the invention is used for adsorption treatment of organic waste water, and has large adsorption capacity, easy separation and recyclable utilization.

In order to achieve the above object, the present invention selects magnesium salt, aluminum salt, nano-iron, and caustic soda as inorganic raw materials, wherein the magnesium salt raw material includes magnesium chloride and magnesium nitrate, the aluminum salt raw material includes aluminum sulfate and aluminum nitrate, and the anionic surfactant includes polyalkylene Sodium benzenesulfonate or sodium polyalkylsulfate. After mixing the anionic surfactant and nano-iron evenly, add it to the mixed solution of aluminum salt and soda ash. Adsorbent materials for organic pollutants, etc.

The specific process is as follows:

The first step, the selection and preparation of raw materials

Add water to commercially available industrial grade magnesium chloride or magnesium nitrate to prepare a solution A with a concentration of 10% to 30% by weight;

Commercially available industrial-grade aluminum nitrate or aluminum sulfate is added with water to prepare a solution B with a concentration of 5% to 30% by weight;

Add water to a commercially available industrial grade anionic surfactant to prepare a solution C with a concentration of 1 to 2% by weight;

Selecting commercially available nano-iron as raw material, adding water to the nano-iron to prepare a solution D with a concentration of 1 to 5% by weight;

Commercially available industrial grade caustic soda is added with water to make solution E with a concentration of 5-20% by weight.

The above-mentioned anionic surfactant is sodium dodecylsulfonate, or sodium tetradecylsulfonate, or sodium hexadecylsulfonate, or sodium octadecylsulfonate, or sodium dodecylbenzenesulfonate .

The above-mentioned nano-iron is commercially available iron powder with a particle diameter of 20nm;

The second step, the preparation of materials

First, take the above-mentioned A, B, C, D, E solutions in equal parts by weight, mix solution C and solution D for 10 to 30 minutes to obtain a liquid, then mix solution B and solution E, stir and dissolve to obtain Another liquid, then mix the two liquids and stir, then slowly add solution A to it, stir and react for 10-30 minutes to obtain a reaction liquid, leave the reaction liquid to stand for 12-24 hours, and finally, in the reactor Place a magnet block at the bottom, discard the clarified solution after 2 hours, and the blue precipitate left at the bottom of the reactor is the material used to adsorb refractory organic pollutants;

Step 3, Preservation or Use of Materials

adding water to the material for adsorbing refractory organic pollutants to prepare a liquid product with a weight percentage of 3-10%, which is directly used for adsorbing refractory organic pollutants;

Or dry and pulverize the material that adsorbs refractory organic pollutants to obtain a powder product that is convenient for storage and transportation.

The above-mentioned placement of the magnet block at the bottom of the reactor is to use a commercially available disc magnet with a diameter of 20 cm and a thickness of 2 cm according to the 3000ml reaction solution. The magnet block is provided by Shanghai Jinkun Magnetic Technology Co., Ltd.

The above-mentioned third step is directly used to adsorb refractory organic pollutants, adding the prepared liquid with a concentration of 3 to 10% by weight to the dye wastewater with a chroma of 10,000 to 100,000 degrees or organic waste with a concentration of 10 to 5,000 mg/l. Material, liquid material dosage is 2-20% volume percentage of the waste water volume, stir for 5-30 minutes, place a magnet with a diameter of 10-20 cm and a thickness of 1-2 cm at the bottom of the waste water for 10-30 minutes to absorb the sediment In order to enrich the residues of organic pollutants, the residues are roasted at high temperature to decompose the adsorbed organic substances to obtain recyclable magnetic inorganic materials.

The advantages of the present invention are as follows:

1. The present invention has the advantages of simple process, readily available raw materials, and low price.

2. The product obtained by the present invention has good adsorption properties to refractory organic pollutants, including basic dyes, cationic dyes, disperse dyes, organic amines, organochlorine and organophosphorus insecticides, bactericides, surfactants, hair dyes Drugs, endocrine disruptors, antibiotics, etc., the adsorption rate is 60-100%.

3. Compared with traditional adsorbents, the materials obtained in the present invention can be directly dispersed into wastewater to absorb organic pollutants, and then separated by magnets without using filtration, centrifugation and other means, with good effect, fast speed, time-saving and power-saving And other advantages, it has great application potential in organic wastewater treatment.

4. The residue after use can be roasted at high temperature to decompose the adsorbed organic matter and prepare a magnetic adsorbent that can be used to adsorb heavy metals.

Detailed ways

Example 1

The first step, the selection and preparation of raw materials

Select commercially available industrial-grade magnesium chloride or magnesium nitrate, add water to it, and prepare a solution with a concentration of 10% by weight, which is referred to as solution A;

Select commercially available industrial-grade aluminum nitrate or aluminum sulfate, add water to it, and prepare a solution with a concentration of 20% by weight, which is referred to as solution B;

Select commercially available industrial-grade sodium dodecylbenzenesulfonate, add water to it, and prepare a solution with a concentration of 1% by weight, which is referred to as solution C;

Select commercially available nano-iron as raw material, the nano-iron is iron powder with a particle size of 20nm, add water to the nano-iron to prepare a solution with a concentration of 1% by weight, referred to as solution D;

Add water to commercially available industrial grade caustic soda to make a solution with a concentration of 5% by weight, which is called solution E for short.

The second step, the preparation of materials

First, take 500ml of each of the above-mentioned solutions A, B, C, D, and E in equal parts by weight, mix solution C and solution D for 20 minutes, then mix solution B and solution E, stir to dissolve, and then mix the two liquids Mix and stir, then slowly add solution A to it, stir and react for 20 minutes, leave the reaction solution to stand and age for 12 hours, and finally, place a magnet block at the bottom of the reactor, discard the clear solution after 2 hours, and leave the solution at the bottom of the reactor The blue precipitate below is the material for adsorbing refractory organic pollutants;

The blue precipitate is formulated into a liquid with a weight percentage of 5% material, which is directly used to adsorb refractory organic pollutants.

Example 2

Adsorption treatment of dye wastewater: Take 1000ml of methylene blue wastewater from a synthetic dye factory in a beaker, add 100ml of the liquid material with a blue appearance and a content of 5% prepared in Example 1, stir for 20 minutes, and stick to the bottom of the beaker Place a magnet block with a diameter of 20 cm and let it stand for 30 minutes. The test results show that the chroma in the raw wastewater is 24500 degrees, the chroma in the clarified liquid after adsorption treatment is 30 degrees, and the removal rate is 99.9%. Therefore, the material has an excellent treatment effect on dye wastewater.

The residue is calcined at 500 degrees for 2 hours to decompose the adsorbed organic matter, and it can still be adsorbed by a magnet after being pulverized into powder, and can be used as a magnetic adsorbent for heavy metals.

Example 3

Adsorption treatment of pesticide wastewater: Take 1000ml of phoxim wastewater from a pesticide factory in a beaker, add 60ml of the liquid material with a blue appearance and a content of 5% prepared in Example 1, stir for 20 minutes, and place it on the bottom of the beaker A magnet block with a diameter of 20 cm was left to stand for 20 minutes. The test results show that the concentration of phoxim in the raw wastewater is 120mg/l, and the concentration of phoxim in the clarified liquid after adsorption treatment is 15mg/l, with a removal rate of 87.5%. Therefore, the material has a good treatment effect on hydrophobic organic waste water.

Claims (2)

1. A method for preparing a material for adsorbing refractory organic pollutants, characterized in that: The first step, raw material selection and preparation Add water to commercially available industrial grade magnesium chloride or magnesium nitrate to prepare a solution A with a weight percent concentration of 10-30%; add water to commercially available industrial grade aluminum nitrate or aluminum sulfate to prepare a weight percent concentration of 5-30%. 30% solution B; add water to a commercially available industrial-grade anionic surfactant to prepare solution C with a concentration of 1 to 2% by weight; add water to nano-iron to prepare a concentration of 1 to 5% by weight Solution D; adding water to commercially available industrial-grade caustic soda to make a concentration of 5% to 20% solution E by weight; The above-mentioned anionic surfactant is sodium dodecylsulfonate, or sodium tetradecylsulfonate, or sodium hexadecylsulfonate, or sodium octadecylsulfonate, or sodium dodecylbenzenesulfonate ; The above-mentioned nano-iron is commercially available iron powder with a particle size of 20nm; The second step, the preparation of materials First, take the above-mentioned A, B, C, D, and E solutions in equal parts by weight, then mix solution C and solution D for 10 to 30 minutes to obtain a liquid, mix solution B and solution E, and stir to dissolve Obtain another liquid, then mix and stir the above two liquids, then slowly add solution A to it, stir and react for 10 to 30 minutes to obtain a reaction liquid, leave the reaction liquid to stand and age for 12 to 24 hours, and finally, in the reaction Place a magnet block at the bottom of the reactor, discard the clarified solution after 2 hours, and the blue precipitate left at the bottom of the reactor is the material for adsorbing refractory organic pollutants; Step 3, Preservation or Use of Materials adding water to the material for adsorbing refractory organic pollutants to prepare a liquid product with a weight percentage of 3-10%, which is directly used for adsorbing refractory organic pollutants; or drying and pulverizing the material for adsorbing refractory organic pollutants, A powder product that is convenient for storage and transportation is obtained. 2. the preparation method of a kind of material that adsorbs refractory organic pollutants according to claim 1, is characterized in that: described place magnet piece at the bottom of reactor, is to use commercially available diameter 20 centimeters, Measured with a 2 cm thick disc magnet.